In the fall of 2016, a team of Pennsylvania STEM educators received a generous grant from the National Science Foundation to provide STEM education to middle-school students in the Philadelphia Promise Zone. Entitled “Philly Scientists” and targeting both classroom teachers and out-of-school time (OST) staff, this grant combined biodiversity curriculum development, teacher training, career access activities, and modern technology to address the following three research questions: 1. What coherent set of experiences effectively support fourth, fifth and sixth grade students’ knowledge development (e.g., biodiversity content knowledge blended with science practices), motivation and career awareness about STEM-related work and jobs of today and the future? What are characteristics of their knowledge, motivation and career awareness competencies? 2. What professional development models and recognition systems can effectively engage teachers and OST providers in demonstrating Next Generation Science knowledge, pedagogy, and career awareness for fourth through sixth grade students? 3. How effective is the activity of Promise Zone fourth-sixth grade students as information providers and Urban Scientists interacting with scientist mentors towards increasing career awareness and understanding characteristics of STEM work? Our partners in this initiative were Drexel University, The Philadelphia Education Fund (PEF), The Academy of Natural Sciences of Drexel University (ANS), and the Pennsylvania Statewide Afterschool/Youth Development Network (PSAYDN). The project also engaged Research for Action (RFA) as the external evaluator. Staff from the Philadelphia Education Fund were primarily tasked with designing, implementing, and evaluating the professional development component of this initiative. The team recognized that in-school and OST teachers have different skill-sets, needs, and schedules - but that each group of educators also has a great deal to offer one another. For instance, we hypothesized that classroom teachers may have more experience connecting lessons to national standards and local educational initiatives; while OST providers may be more versed in working with families, with communities, and with blending social work and education. For these reasons, we were interested in both the logistical and pedagogical results and implications of our study. And while there is a great deal of research pertaining to STEM professional development for both in-school and out-of-school staff, we found little literature that referenced blending PD for both populations.